CAN Communication Circuit Inspection

1. CHECK CONNECTOR 
   1. Turn ignition switch OFF.
   2. Disconnect the battery cable from the negative terminal.
   3. Disconnect the harness connector for each unit on the CAN network and check terminals for deformation, disconnection, looseness or damage.

   OK or NG 

   • OK: GO TO 2.
   • NG: Repair or replace as necessary.
2. CHECK HARNESS FOR SHORT CIRCUIT 

   With all module and control unit connectors disconnected, check continuity between data link connector terminals.

   DATA LINK CONNECTOR TERMINAL CONTINUITY CHART
   
   

   Data link connector	Terminal		Continuity
   M8	6	14	No

   Fig 1: Identifying Continuity Between Data Link Connector Terminals 14 And 6

   Courtesy of NISSAN MOTOR CO., U.S.A.

   OK or NG 

   • OK: GO TO 3.
   • NG:
     • Repair harness.
     • Change harness if shielded lines are used for the harness.
3. CHECK HARNESS FOR SHORT CIRCUIT 

   Check continuity between data link connector and ground.

   DATA LINK CONNECTOR TERMINAL CONTINUITY CHART
   
   

   Data link connector	Terminal	Ground	Continuity
   M8	6		No
   	14		No

   Fig 2: Identifying Continuity Between Data Link Connector And Ground

   Courtesy of NISSAN MOTOR CO., U.S.A.

   OK or NG 

   • OK: GO TO 4.
   • NG:
     • Repair harness.
     • Change harness if shielded lines are used for the harness.
4. ECM AND IPDM E/R INTERNAL CIRCUIT INSPECTION 
   1. Remove ECM and IPDM E/R from vehicle.
   2. Check resistance between ECM terminals.
      TERMINAL RESISTANCE CHART
      
      

      Terminal		Resistance (Approx.)
      94	86	108 - 132 ohm

   3. Check resistance between IPDM E/R terminals.
      TERMINAL RESISTANCE CHART
      
      

      Terminal		Resistance (Approx.)
      48	49	108 - 132 ohm

      Fig 3: Identifying Resistance Between IPDM E/R Terminals

      Courtesy of NISSAN MOTOR CO., U.S.A.

      OK or NG 

      • OK: GO TO 5.
      • NG: Replace ECM and/or IPDM E/R.
5. CHECK SYMPTOM 
   1. Fill in described symptoms on the column "Symptom" in the check sheet.
   2. Connect all connectors, and then make sure that the symptom is reproduced.

   OK or NG 

   • OK: GO TO 6.
   • NG: Refer to "EXAMPLE OF FILLING IN CHECK SHEET WHEN INITIAL CONDITIONS ARE NOT REPRODUCED ".
6. UNIT REPRODUCIBILITY INSPECTION 

   Perform the following procedure for each unit on the CAN network, and then perform reproducibility test.

   1. Turn ignition switch OFF.
   2. Disconnect the negative battery terminal.
   3. Disconnect the unit connector.
   4. Connect the battery cable to the negative terminal.
   5. Make sure that the symptom filled in the "Symptom" of the check sheet is reproduced. (Do not confuse it with the symptom related to removed unit.)
   6. Make sure that the same symptom is reproduced.

Inspection results 

Reproduced>>Install removed unit, and then check the other unit.

Not reproduced>>Replace removed unit.